At present, with the development of the electronic technology, more and more electronic products need to deal with various complicated environments. For example, as a daily article, a mobile phone needs to consider how to keep water out. In particular, a connector for the mobile phone needs to be inserted with or extracted from an external plug frequently, so that an insertion port of the connector needs to be exposed to external environment. When the mobile phone is in water environment, water may get inside the connector from the insertion port of the connector, and further get inside the mobile phone through the connector, which will result in a security incident. Currently there is no waterproof cover to prevent water from flowing into the mobile phone through the connector.